Vertical linear lock for circular motion testing machine



WW I 3 93mm SEARCH RM June 5, 1962 G. F. HILL 3,03 8

VERTICAL LINEAR LOCK FOR CIRCULAR MOTION TESTING MACHINE Filed Dec. 5,,1960 2 Sheets-Sheet 1 V I l I l 1 I a m N N8 a l I q 53' 3 it 3 ma NI:

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GlLBERT F. HILL BY @Ikhmmw June 5, 1962 VERTICAL LINEAR LOCK FOR Filed Dec. 5, 1960 F. HILL 3,037,378

CIRCULAR MOTION TESTING MACHINE 2 Sheets-Sheet 2 INVENTOR.

GILBERT F HILL BY MMSLMKQW.

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United States 3,037,378 VERTICAL LINEAR LOCK FOR CIRCULAR MOTION TESTING MACHINE Gilbert F. Hill, Skaneateles, N .Y., assignor to LAB. forporation, Skaneateles, N.Y., a corporation of New ersey Filed Dec. 5, 1960, Ser. No. 73,793 2 Claims. (Cl. 73-71.6)

This invention relates generally to vibration test equipment, and more particularly to a novel mechanical brute-force type vibrator easily and selectively adapted for circular synchronous motion or vertical straight line reciprocal motion.

Testing machines of this type are particularly useful in simulating the vibration to which packaged articles are subjected during transportation, whether it be by train, truck or airplane. The article to be tested is placed on a carrier table or platform which is then subjected to vibrations induced in the platform by eccentrics mounted on motor driven shafts.

Since the vibrations to which a packaged article is most frequently subjected are a combination of vertical shocks and side to side motions, machines which produce a combination of such motions, comprising a circular synchronous motion, are most frequently used for transportation simulating purposes. Such machines may comprise the usual platform mounted on rigid legs which are given a circular motion in vertical planes by mounting them on eccentrics which are driven synchronously.

Since the most frequent shocks to which a packaged article is subjected are usually the vertical ones, testing machines which only vibrate the platform substantially vertically are also in demand. Such machines may be conveniently made by an adaptation of the circular synchronous machine. The rigid legs of the latter machines are given a pivot on an axis normal to the plane of the circular motion and the platform is anchored so as to be restrained from side-to-side motion by a substantially horizontal lever pivoted at either end whereby the platform remains free to rise and fall substantially vertically.

Machines have been developed heretofore which may be selectively adapted for both circular synchronous vibration and for vertical vibration. By providing a sideto-side pivot to disable the horizontal stabilizing lever and bolt means to selectively render this disabling pivot ineffective, and by providing bolt means for disabling the leg pivots, machines have been adapted for alternative use as circular synchronous or vertical linear vibrators.

Such machines are subject to various defects. The bolts are located under the machine and are difficult to get at. Considerable time is necessary to convert the machine from one type of motion to the other. Frequently one set of bolts may be inserted and one or more bolts of the other set may not be removed resulting in shearing of the bolts and damage to the machine. Furthermore bearing clearances, which are necessary when pivots are provided, result in distortion of the theoretically imparted motion and the use of bolts in itself may result in a similar distortion of the desired motion.

The principal object of the present invention is, therefore, to provide a vibration-imparting testing machine which may be quickly and easily converted from a circular synchronous motion vibrator to a vertical linear motion vibrator, and vice versa.

Further objects are to provide such a machine which is economically constructed, in which the conversion from one type of motion to the other is made by external controls and in which it is impossible to disable one portion 3,@37,378 Patented June 5, 19482 of the mechanism without freeing the other portion, thus preventing accidental breakage.

A still further object is to provide a machine in which the disabling mechanism for each type of motion effectively locks the disabled pivots against unwanted play occasioned by bearing clearances.

Other objects and advantages will become apparent from the following description taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a side elevational view of a machine embodying the present invention, certain parts being shown in section on the line 11 of FIGURE 2 and being positioned for circular synchronous motion;

FIGURE 2 is a fragmentary plan view of one side of the machine of FIGURE 1 with the platform removed;

FIGURE 3 is a view similar to FIGURE 1 showing a portion of the machine with the parts adjusted for verti cal linear motion;

FIGURE 4 is a fragmentary sectional view taken substantially along line 44 of FIGURE 1;

FIGURE 5 is a fragmentary sectional view taken substantially along line 5'5 of FIGURE 1; and

FIGURE 6 is a fragmentary sectional view taken substantially along line 6-6 of FIGURE 1.

Referring more particularly to FIGURES l and 2 the vibrator 10 is shown as having a rectangular base 11 of welded channel construction adapted to be bolted to a floor and a rectangular platform 12 of approximately the same size, generally of rectangular tubular members 13 welded into a sub-floor to which wooden planks 14 are bolted to simulate the usual train or truck floor.

The platform 12 has one of the inverted U-shaped brackets 15 and 16 bolted thereto at 17, at each of the four corners. Each bracket has a depending leg or connecting link 20 pivotally secured thereto for supporting the platform on the base. The connecting link 20 is embraced between the pendant sides of each bracket and a pivot pin 21 extends therethrough. An appropriate heavy duty bearing 22 is provided for each link.

Each link 20 at its lower end has a larger bearing 23 and is rotatably supported on an eccentric 24 on one of two shafts 25. The shafts 25 extend across the machine at either end and are rotatably supported in the usual pillow block bearing supports 26 which are bolted or otherwise secured to the base 11.

It will be understood that the shafts 25 are provided with sprockets outside the base frame with a connecting chain and means including a motor, all not shown, or with other means for synchronously rotating the two shafts 25.

Brackets 15 and 16 on each side of the machine may be braced by a connecting bar 27 secured to the brackets at either end as shown in FIGURE 2, the other side of the machine being a mirror image of the side shown in FIGURE 2.

The two brackets 15 at one end of the machine are longer than the brackets 16 at the other end for also embracing the pendant stabilizing links 30 which are pivotally secured to the brackets 15 by the pins 31 and are provided with suitable bearings 32.

The lower end of each link 30 is bifurcated or provided with a central slot 33 as shown (FIGURE 5), and a substantially horizontal guide link 35 is pivotally secured in the slot by a pin 36, a suitable bearing 37 being provided. The other end of link 35 is similarly pivotally secured in a forked bracket 38, provided with a slot 39 (FIGURE 6), a pin 40 and bearing 41. Bracket 38 is welded or otherwise secured to base 11.

Above the links 20 and 30 in the brackets 15, there is also provided a sliding stop or lock element for selectively locking or disabling the pivots 21 or 31 of the links 20 and 30 respectively. Lock element 45 is generally wedge-shaped and its downwardly facing wedge surfaces 46 and 47 are adapted to engage and lock against the slightly inclined top surfaces 48 and 4-9 of the links 20 and 30 as the element 45 is moved to the right (FIGURE 1) or left (FIGURE 3) and the links 20 and 30 are vertically disposed.

For moving the lock 45 back or forth, a rod '50 is provided, threadedly engaged with lock 45 and supported in the platform 12 by straps 51 and 52 welded or otherwise secured to the bracket 15 and depending angle iron 53 of the platform, respectively. Collars 54 locked to rod 50 are provided on either side of the strap 51 so that the rod 56 may act as a worm to advance or withdraw lock element 45.

A sprocket 55 is secured to each worm 50 and a chain 56 may connect the sprockets so the two locking mechanisms can be operated as a unit. A ha n cfl e.57 is provided at the outside of the machine for turning each worm 50.

It will be apparent that other mechanism such as an eccentric pivoted lever or hydraulic means could equally well be used to operate the lock 45.

The operation of the machine will now be apparent. When the lock 45 is moved to the right as shown in FIG- URE l, the machine operates as a circular synchronous vibrator. The surface 46 on the lock element engages surface 48 on the connecting link 20 and effectively locks link 20 in vertical position by disabling the pivot 21. When rotary motion in unison is imparted to the shafts 25 the platform 12 is carried by the now rigid legs 20 in a circular vibratory path by the eccentrics 24.

When the lock 45 is moved to the left as shown in FIGURE 3, the pivot 21 is freed and surface 47 of the lock engages surface 49 on the stabilizing link 30, locking the link in a vertical position and effectively disabling pivot 31. The connecting links 20, now being pivoted at 21, the platform 12 rises and falls with the eccentrics 24 but is restrained from side to side motion by the guide link 35. The motion of the platform is substantially a vertical, straight line reciprocatory vibration, actually slightly arcuate since the pivot 36 moves on an are, but for all practical purposes in a straight line.

When the lock is moved to disable pivot 21 as in FIG- URE l, the connecting linkage is thereby disabled since the link 20 becomes a rigid leg. Freeing of the pivot 31 also renders the stabilizing linkage inoperative, since the stabilizing linkage, comprising links 30 and 35, is only effective when the pivot 31 is disabled and the link 30 is locked to the platform as in FIGURE 3.

Moving the lock 45 to the left, however, makes both the connecting linkage and stabilizing linkage effective again by disabling pivot 31 and freeing pivot 21 to make the connecting link 20 effective as a link.

It will now be seen that there has been provided a vibrator which can quickly and easily be converted from circular synchronous to straight line reciprocal motion, which is trouble free in that the same locking element locks one linkage while freeing the other, and which eliminates any play caused by bearing clearance in the locked pivot by effectively clamping the pivoted member against the pivot itself.

As will be apparent to those familiar with the art, the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The embodiment disclosed is therefore to be considered in all respects as illustrative rather than restrictive, the scope of the invention being indicated by the appended claims.

What is claimed is:

1. In a vibration testing machine having a base, a platform, means for supporting said platform on said base including at least one leg, at least one shaft rotatably mounted on said base and having an eccentric thereon, said leg being rotatably mounted on said eccentric; the improvement comprising at least one pendant stabilizing link pivotally secured to said platform at one end and pivotally connected to a substantially horizontal guide link at the other end, the other end of said guide link being pivotally secured to said base, said leg being pivotally secured to said platform adjacent said stabilizing link, said pivotal connections being axially parallel to the axis of said shaft, stop means movably mounted on said platform between said leg and said stabilizing link,

7 and means for moving and securing said stop means from a first position engaging and locking said leg with respect to the platform, to a second position engaging and locking said stabilizing link with respect to the platform whereby said machine is adapted for circular synchronous motion when said stop member is in said first position and adapted for vertical linear motion when said stop member is in said second position.

2. A vibration testing machine having a base, synchronously rotating shafts supported at either end thereof,

gqfintrifimql heach shaft at the four corners of the machine, a platfofififan upstanding connecting link ro-" 35 tatably supported on e agl egc entric, each link being pivotally connected to said platform, pendant stabilizing links pivotally secured to said platform adjacent the legs at one end of said machine, a substantially horizontal guide link pivotally connected at one end to each of said stabilizing links and at the other end to said base, a wedge-shaped stop member horizontally slidable in said platform between each stabilizing link and the adjacent leg, a worm threadedly engaged with each of said stop members, and means located adjacent an edge of said platform for turning said Worm, said stop member being movable from a first position engaged with at least one of said connecting links for disabling the pivoted connection thereof to said platform to a second position engaged with said pendant stabilizing link for disabling the pivoted connection of said stabilizing link with said platform.

References Cited in the file of this patent UNITED STATES PATENTS 

